The nutritional intake of Tibetan sheep on the harsh Qinghai-Tibetan Plateau (QTP) is often under maintenance requirements, especially during the long, cold winter. However, they have adapted well and even thrive under these conditions. The aim of this study was to gain insight into how the rumen epithelium of Tibetan sheep has adapted to the consumption of low energy level diets. For this purpose, we compared Tibetan and Small-tailed Han sheep (n = 24 of each breed, all wethers and 1.5 years of age), which were divided randomly into one of four groups and offered ad libitum diets of different digestible energy (DE) densities: 8.21, 9.33, 10.45 and 11.57 MJ DE/kg dry matter (DM). The Tibetan sheep had higher rumen concentrations of total SCFAs, acetate, butyrate and iso-acids but lower concentrations of propionate than Small-tailed Han sheep. The Tibetan sheep had higher absorption capability of SCFAs due to the greater absorption surface area and higher mRNA expression of the SCFAs absorption relative genes than Small-tailed Han sheep. For the metabolism of SCFAs in the rumen epithelium, the Small-tailed Han sheep showed higher utilization of the ketogenesis pathway than Tibetan sheep, however, Tibetan sheep had greater regulation capacity in SCFAs metabolism pathways. These differences between breeds allowed the Tibetan sheep to have greater capability of absorbing SCFAs and better capacity to regulate the metabolism of SCFAs, which would allow them to cope with low energy intake better than Small-tailed Han sheep.